I *think*, based on the note to the sister, the fact that the height measurements abruptly sopped, and the fact that the letter from him to the dad in the secret compartment was ripped up... that Oscar sexually abused the dad (who was his nephew). Something along those lines. He gave away the pharmacy because he felt bad for what he did, and as a result of living in his house by himself for a long time that was why he was lonely. This is my own speculation based on the information in the letter found in the basement safe.

This is some really interesting stuff. Watching the videos as they've been released has provided some crazy insight to the world of video game development. In this video Greg Rice said that at one point during the Iron Brigade development a guy came down from Microsoft and said that they were going to cancel the game if they couldn't get it out by a certain point in time. Shit like this probably happens all of the time, the difference is we actually get to see it unfold.